I'd suggest to set click types at the lowest reading. If the lowest reading is 50 ft-lbs., stop there. Don't unwind the handle till it stops because the internal components can slip if there is no tension on them.
Electronic torque wrenches, which are becoming more popular, do not need to be...
I see another year or two has passed, but I'll put in a little info for what it's worth.
I work in a calibration lab, and take torque wrenches apart every day or so. Usually nothing as old as what you have, and technology has advanced a bit. Instead of triangle things, most everybody uses...